by Francisco Laso
Francisco received his B.A. in Environmental Biology from Columbia University in 2008. He melds science and art in his attempt to broaden the scientific community’s sphere of influence. He is currently working for the Network of Conservation Educators and Practitioners (NCEP) at the American Museum of Natural History (AMNH).
These images were captured during the summer of 2007 as part of an ongoing study that addresses habitat and community dynamics from broad to narrow ecological vantage points. Amazonian river turtles are ecologically important as they play an essential role in the seed dispersal of several fruit tree species in the flooded plain. These turtles also have religious, cultural, and economic significance for indigenous river communities. The endangered Amazonian river turtles Podocnemis expansa, P. unifilis, and P. sextuberculata are a local delicacy in Iquitos, Peru. Despite their importance and familiarity to people, we know very little about these species and commercial exploitation has decimated turtle populations outside natural reserves. Conservation of these species is aimed at the sustained wellbeing of the flooded forest ecosystem and its inhabitants. The hope is that future generations will inherit the success of our good stewardship rather than the failings of our negligence.
The following is a selection from a group of pictures that was taken for a visual manual to be used by researchers, park officials, and river communities. The photo-manual is meant to serve researchers and conservationists in recognizing the basic physiology and biology of the three turtle species, learning basic blood sampling techniques, qualifying threats for extinction, and proposing strategies for conservation.
Keywords: Testudines, Podocnemididae, Podocnemis, Turtle, Amazon, Iquitos.
Challenges to the Conservation of River Turtles (spp. Podocnemis) in the Peruvian Amazon
June-August 2007, Iquitos, Peru. Created with the support of the Kluge Fellows Summer Research Program.
The Amazonian river turtles, Podocnemis expansa, P. unifilis, and P. sextuberculata, have long been of great ecological, economic, and cultural importance for the Amazon rainforest and its inhabitants. All three species were once known for their astonishingly large population sizes all over the Amazon River basin. Today, they are a rare sight and are listed as species of conservation concern on several international endangered species listings. Most inhabitants of river communities in the Peruvian Amazon, who have hunted turtles for their meat and eggs for centuries, are aware of the severe drop in turtle populations during the past few decades. River community members identified the cause of the turtles’ disappearance to be the unsustainable commercial exploitation of this resource to meet the growing demands of large urban areas such as Iquitos, Peru.
Tourism is one of Iquitos’ main economic strengths, and much of the increasing demand for wildlife meat comes from tourists with adventurous palates. After having extirpated turtle populations for miles around Iquitos, turtles, especially rare specimens such as giant river turtles (P. expansa), are likely to be brought from within Peru’s largest protected area, the Pacaya-Samiria National Reserve (RNPS). Unfortunately, current regulations and conservation efforts are insufficient. An anonymous RNPS park ranger explained that his organization is often unable to handle illegal activities like poaching and logging on its own because of fuel scarcity and conflict with armed offenders is dangerous. As a result, authorities rarely intercept turtles that are smuggled into Iquitos in the cargo of transportation barge passengers.
The genus Podocnemis is a primitive one, and it has evolved through millions of years to become intricately integrated with the flooded forest ecosystem. Since the turtles are important seed dispersers, scavengers, and sources of food for other predators, their disappearance has profound ecological implications. Historically, fresh water turtles can reach very high biomasses and densities, which can give us an idea about their significant contribution to nutrient cycling and to energy flow patterns in both lakes and rivers (Moll, 1990). In tropical forests, most plants produce fruit during the flooding season, and 70-90% of plant species are vertebrate-dispersed (Ganesh and Davidar, 1999); Podocnemis turtles have the potential to be high-quality seed dispersers because their diet is predominantly comprised of fruits, which are swallowed whole and generally pass unharmed (Moll and Moll, 2004). Seeds that have been ingested by turtles actually fare better than non-ingested seeds as turtles carry them away from the parent tree and are fertilized by the nutrients in turtle droppings (Moll and Jansen, 1995). The most important factor to determine the extent to which Podocnemis turtles fulfill their role as one of the flooded forest’s key seed dispersers is the density of turtle populations. It is probable that the consequences of the sudden disappearance of this genus from the Amazon Basin ecosystems are not yet fully perceptible because the cycles that are being disrupted by the unfulfilled niches of these turtles occur at larger time scales than humans can effectively perceive. The sheer longevity of fruit trees that depend on turtles to disperse their seeds is enough to camouflage their disrupted life cycles.
The ramifications of these turtle species’ extinctions goes well beyond bottom lines of fishermen and market vendors. Their survival or demise might influence the existence of the flooded forest itself and of all the life, resources, and ecological services it provides. The crucial role that these turtles play in the life cycles of Amazon plant species binds their destiny to both local and global processes. It ranges from a single tree providing food and a habitat to the entire flooded forest acting as a carbon sink, regulating global climate and producing the oxygen we breathe. After just a couple centuries of rapid anthropogenic growth in the area, these species are likely to face extinction if their situation is ignored. This resource urgently needs to be managed with improved information and organization.
Bendayán, Acosta. 1991. Influencia Socioeconomica de la Fauna Silvestre como Recurso Alimentario – Iquitos. Universidad nacional de la Amazonia Peruana, Facultad de Ciencias Biologicas.
INEI 2002. Peru: Proyecciones de Poblacion por años calendario segun Departamentos, Provincias y Distritos. Lima, Instituto Nacional de Estadistica e Informatica.
Moll, D. and K. P. Jansen (1995). “Evidence for a Role in Seed Dispersal by 2 Tropical Herbivorous Turtles.” Biotropica 27(1): 121-127.
Moll, D. 1990. “Population Sizes and Foraging Ecology in a Tropical Fresh-Water Stream Turtle Community.” Journal of Herpetology 24(1): 48-53.
Moll, Don and Moll, Edward. “River Turtles” New York: Oxford University Press, 2004.